During the past year, the VRC's Vector Core created and tested new vaccine vectors expressing different HIV protein, including structural and envelope proteins. In addition,different methods and routes of administration as well as prime/boost combinations were tested to further optimize HIV vaccine strategies. New adenoviral,LCMV and BCG vectors were tested, as well as administration via intradermal and mucosal delivery. Several candidate vaccines elicited promising immunogenicity data in preliminary studies and are being tested further. Antibodies that inhibit or prevent infection were developed,and initial testing performed. Specific accomplishments include: Assessment of recombinant lymphocytic choriomeningitis virus (rLCMV)as a vaccine to prevent HIV infections. Different prime boost vectors encoding HIV-1 Env including DNA, recombinant adenovirus serotype 5 (rAd5) or alternative serotype rAd for priming followed by boosting with a replication-defective vector were compared. T cell immunogenicity was assessed by intracellular cytokine staining or by analyzing tetramer positive cells.